The State Department, which has been on the leading edge of policies affecting lesbian, gay, bisexual and transgender federal employees, is eliminating the “transgender exclusion” from the agency’s largest health insurance program.

Insurance policies under the Federal Employees Health Benefits program generally exclude services “related to sex reassignment.”

In practice, this transgender exclusion “denies coverage to transgender people for the same treatments available to non-transgender policy holders, without regard to medical necessity,” the State Department said in a statement. “Insurance companies often view this exclusion in the broadest possible terms, excluding care that clearly has no relationship to gender status such as cancer treatment and routine preventive care.”

But starting in January, the exclusions will no longer be part of the department’s largest health insurance plan, the one provided by the American Foreign Service Protective Association.

This will make a big difference for the family of Kimi Kanda in Santa Clara, Calif.

“Because the exclusion in federal health-care coverage has been lifted, our daughter will have access to health care she needs like any other child of a federal employee,” Kanda said. “If the exclusion remained, we would pay out of pocket for her medical care even though we already pay for her to be included on my husband’s federal insurance.”

The State Department has about a dozen health insurance providers. All of them have been asked to lift the transgender exclusion, and AFSPA’s Foreign Service Benefit Plan is the first to comply. The State Department said the Foreign Service Benefit Plan covers more than 57,000 active and retired State Department and Defense Department employees and their families.

“It’s about fairness and respect for our employees, but it’s also about showing the world we mean what we say and say what we mean,” Secretary of State John F. Kerry said in a statement to The Washington Post. “It’s tough to tell other countries to provide equal opportunity if we’re not living that out ourselves. So this matters in many ways. I’ve met transgendered colleagues at the Department and in addition to being brave and strong, they’re just good officers. Why should they have it any different when it comes to health care?”

The AFSPA plan is the department’s largest, covering almost 31 percent of its employees, with Blue Cross Blue Shield a close second.

Paula S. Jakub, AFSPA’s chief executive, said the association has “been working tirelessly” with the Office of Personnel Management (OPM) and others “for the last two years to make this benefit a reality.”

But it is not a reality for other plans in the OPM-administered federal health-benefits program. OPM said it “removed its requirement that carriers exclude ‘services, drugs, or supplies related to sex transformations’ ” beginning in 2015, but it did not order health insurance companies to do so.

Selim Ariturk, president of GLIFAA, which represents LGBT State Department employees, praised OPM and AFSPA “for doing the right thing, and ending this discrimination. All our colleagues deserve equal access to quality health care.” GLIFAA once stood for “Gays and Lesbians in Foreign Affairs Agencies,” but it now uses just the initials because, Ariturk said, “we’re pushing for equality for all, not just the ‘G’s and L’s.’”